Answer:
the top of the ladder is 27.5ft above the ground.
Explanation:
The ladder makes an angle, θ with the ground thus forming a right angle triangle with the wall of the house.
The length of the ladder represents the hypotenuse of the right angle triangle.
The ground distance from the base of the wall to the foot of the ladder represents the adjacent side of the right angle triangle.
Therefore, to determine how high up is the top of the ladder on the wall, x, we would apply Pythagoras theorem which is expressed as
Hypotenuse² = opposite side² + adjacent side²
28² = x² + 5²
784 = x² + 25
x² = 784 - 25 = 759
x = √759 = 27.5ft